Process parameter optimisation of a minster draw‐redraw system

Abstract

Non‐conformance in Unit Depth Value (UDV) of expansion rings for metal cans makes them prone to major defects, such as swells and distortions, during the Drawing/Redrawing industrial process. In this paper, with the aim of improving the manufacturing process quality, the process parameters for the Minster Draw/Redraw machine at a generic company are optimised so as to obtain the desired UDV. The Taguchi method is used to determine the most influential process parameters. Nine experiments have been performed with four selected parameters, namely, Upper Blank Holder Pressure, Lower Blank Holder Pressure, Profile Pad Pressure, and Inner Ram Value. A multiple‐linear regression analysis is also conducted to demonstrate the relationship between UDV and the considered parameters. The best settings for the respective process parameters are obtained via Analysis of Means (ANOM). Furthermore, Analysis of Variance (ANOVA) shows that the Inner Ram Value is the process parameter that most significantly affects the formation of expansion rings. The same methodology proposed in this study can easily be extended to find the optimum settings of process parameters for different can heights. Finally, an equation is formulated to predict the setting values of the most significant process parameters under user‐specified UDVs.